1. Field of the Invention
This invention relates to an apparatus and a method for data decoding, and more particularly, to a decoding device applied in an optical disc drive and a related decoding method thereof.
2. Description of the Prior Art
Please refer to FIG. 1: FIG. 1 is a block diagram of the conventional DVD playback system 100. As shown in FIG. 1, the DVD playback system 100 includes an EFM+ demodulator 110, a main data storage device 120, a decoding device 130, a decoding result confirmation unit 140, an ATAPI interface unit 150, and a bus 160. The decoding device 130 includes an inner-code parity (PI) syndrome generator 132, a PI error correction unit 134, an outer-code parity (PO) syndrome generator 136, a PO error correction unit 138, and a decoding unit 139. After the playback system 100 reads data from a disc 101 (e.g. a DVD disc), the data will be demodulated by the EFM+ demodulator unit 110 and then stored in the main data storage device 120. The PI syndrome generator 132 reads the data progressively from the main storage device 120 through the bus 160 according to the PI direction (i.e. the horizontal direction) and then generates the PI syndrome. Accordingly, the decoding unit 139 (e.g. the Reed Solomon Product Code (RSPC) decoder) executes the inner-code parity decoding process to the data according to the PI syndrome. According to the decoding result, the PI error address and PI error value generated by the decoding unit 139 are sent to the PI error correction unit 134.
The PI error correction unit 134 then executes the data error correction process to the data by the PI direction, and restores the corrected data into the main storage device 120 through the bus 160. The PO syndrome generator 136 reads the data discontinuously from the main storage device 120 through the bus 160 according to the PO direction (i.e. the vertical direction) and then generates the PO syndrome. Accordingly, the decoding unit 139 executes the outer-code parity decoding process to the data according to the PO syndrome. According to the decoding result, the PO error address and PO error value generated by the decoding unit 139 are sent to the PO error correction unit 138. The PO error correction unit 138 then executes the data error correction process to the data by the PO direction and restores the corrected data into the main storage device 120 through the bus 160. The decoding result confirmation unit 140 (e.g. a descramble and EDC check unit) thus reads data from the main data storage device 120 to check whether the error-correction procedure is completed. If the decoding result confirmation unit 140 determines that the data stored in the main data storage device 120 is correct, the conventional DVD playback system 100 will transfer the data from the main data storage device 120 to a host by means of the ATAPI interface unit 150.